Methods of treating hot flashes with formulations for transdermal or transmucosal application

ABSTRACT

The present invention relates generally to methods for treating hot flashes by administering formulations for transdermal or transmucosal administration of estrogen. The formulations of the invention are effective at treating hot flashes at surprisingly low daily doses, preferably the lowest effective dose of estrogen to treat hot flashes, e.g., about 0.45 to about 0.6 mg of estrogen per day. The amount of estrogen which is administered produces an estimated nominal daily estrogen dose in a subject undergoing treatment of from about 10 to about 15 micrograms, and a serum estradiol level of between about 25 pg/ml to about 50 pg/ml. The preferred formulations are substantially free of malodorous, and irritation causing long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/737,389filed Apr. 19, 2007, which claims the benefit of provisional application60/794,015 filed Apr. 21, 2006. The entire content of each applicationis expressly incorporated herein by reference thereto.

FIELD OF INVENTION

The present invention relates generally a method for treating hotflashes by administering formulations for the transdermal ortransmucosal delivery of estrogen. The formulations of the invention areeffective at treating hot flashes at surprisingly low daily doses,preferably the lowest effective dose of estrogen that is effective attreating hot flashes. The preferred formulation comprises estrogen, analcohol, a polyalcohol, and a permeation enhancer. Preferably, theformulation is substantially free of malodorous, and irritation causinglong-chain fatty alcohols, long-chain fatty acids, and long-chain fattyesters, and delivers effective therapeutic levels of estrogen.

BACKGROUND ART

Transdermal and/or transmucosal delivery of active agents provide aconvenient, pain-free, and non-invasive method of administering activeagents to a subject. Additionally, the administration of active agents,such as drugs, through the skin or mucosal surface avoids thewell-documented problems associated with the “first pass effect”encountered by oral administration of active agents. As known in theart, orally administered drugs are absorbed and enter the bloodstreamwhere they are transported by the portal vein directly to the liverbefore entering the general circulation of the body. If the drug issubject to a high hepatic clearance, i.e., it is rapidly metabolized bythe liver, then a substantial fraction of the absorbed dose is extractedfrom the blood and metabolized before it ever reaches the systemiccirculation. A consequence of this “first pass effect” phenomenon is asignificant reduction in the bioavailability of the drug. In someinstances, the first pass effect is so large as to render oraladministration of a drug ineffective. Furthermore, all the orallyabsorbed drug is concentrated in the portal vein producing a much higherconcentration in portal blood than the corresponding systemic levels. Inthe case of steroidal hormones, including estrogens, the primary concernof the higher portal vein concentrations of the drug is a greaterdose-dependant genomic effect on liver protein synthesis than thetransdermal and transmucosal delivery systems. For a period of time, inthe order of months, these very high hormone levels in the portal veinquickly and significantly stimulate the production of higher circulatinglevels of thrombogenic clotting protein factors and free fatty acids.This phenomenon is not seen to the same extent with transdermaladministration as the hormone absorbed transdermally reaches the liverat the lower systemic hormone level eliminating this fast increase inprotein and fatty acid production.

Although the transdermal and/or transmucosal delivery of active agentsovercome some of the problems associated with oral administration ofactive agents, such as that described above, they are not free of theirown drawbacks. Problematically, transdermal drug delivery systems aretypically restricted to low-molecular weight drugs and those withstructures having the proper lipophilic/hydrophilic balance. Highmolecular weight drugs, or drugs with too high or low hydrophilicbalance, often cannot be incorporated into current transdermal systemsin concentrations high enough to overcome their impermeability throughthe stratum corneum. Specifically, polar drugs tend to penetrate theskin too slowly, and since most drugs are of a polar nature, thislimitation is significant.

Efforts have been made in the art to chemically modify the barrierproperties of skin to permit the penetration of certain agents (sincediffusion is primarily controlled through the stratum corneum), enhancethe effectiveness of the agent being delivered, enhance delivery times,reduce the dosages delivered, reduce the side effects from variousdelivery methods, reduce patient reactions, and so forth.

In this regard, penetration enhancers have been used to increase thepermeability of the dermal surface to drugs, and are often protonsaccepting solvents such as dimethyl sulfoxide (DMSO) anddimethylacetamide. Other penetration enhancers that have been studiedand reported as effective include 2-pyrrolidine, N,N-diethyl-m-toluamide(Deet), 1-dodecal-azacycloheptane-2-one N,N-dimethylformamide,N-methyl-2-pyrrolidine, calcium thioglycolate, hexanol, fatty acids andesters, pyrrolidone derivatives, derivatives of 1,3-dioxanes and1,3-dioxolanes, 1-N-dodecyl-2-pyrrolidone-5-carboxylic acid,2-pentyl-2-oxo-pyrrolidineacetic acid,2-dodecyl-2-oxo-1-pyrrolidineacetic acid,1-azacycloheptan-2-one-2-dodecylacetic acid, and aminoalcoholderivatives, including derivatives of 1,3-dioxanes, among others.

The penetration enhancers used and thought to be necessary totransdermally deliver active agents such as steroid hormones, namely,compounds such as long chain fatty acids such as oleic acids, fattyalcohols such as lauryl alcohol and long-chain fatty esters such asisopropyl myristate, tend to include aliphatic groups that make theformulations oily and malodorous.

For example, U.S. Pat. No. 5,891,462 teaches the use of lauryl alcoholas a permeation enhancer for estradiol and norethindrone acetate. Suchformulations are not appealing to the user nor to anyone else in closeproximity to the user. Although this particular patent discloses threeexamples of estradiol or norethindrone acetate formulations having nolauryl alcohol component, such formulations are comparative examplesthat are intended to illustrate the long held position that long chainfatty alcohols such as lauryl alcohol are necessary to transdermallydeliver norethindrone acetate in combination with estradiol to asubject.

Additionally, for example, the known testosterone gel formulationsFORTIGEL® and TOSTRELLE® (Cellegy Pharma, South San Francisco, Calif.),both include ethanol, propanol, propylene glycol, carbomer,triethanolamine, purified water, and oleic acid as a permeationenhancer, the latter being responsible for the irritating and malodorouscharacteristics of these formulations. Also, TESTIM® (AuxiliumPharmaceuticals, Norristown, Pa.) is a 1% testosterone gel and includespentadecalactone, acrylates, glycerin, polyethylene glycol (PEG), andpentadecalactone as a permeation enhancer. It is a very odoriferouscompound. Also, TESTIM® is not desirable because it contains undesirableamounts of glycerin which are not well tolerated by the skin.

Thus, there is a need for a transdermal formulation that adequatelydelivers active agents to patients with skin tolerability, but does notinclude the unpleasant odor common to the prior art formulations.

SUMMARY OF THE INVENTION

The present invention provides methods and compositions for treating hotflashes, by administering to a subject in need of such treatment atopical or transmucosal formulation, the formulation comprising anamount of estrogen which is effective at treating hot flashes, and atopically or transmucosally acceptable delivery vehicle. As demonstratedherein, the Applicants have found that the formulations are effective attreating hot flashes at surprisingly low daily dosages. In accordancewith the invention, the amount of estrogen in the formulation is thelowest effective dose which is effective at treating hot flashes in asubject in need thereof. As used herein, the term “lowest effectivedose” is the daily dose that is effective at treating hot flashes, underwhich there is no lower effective dose.

For example, it has unexpectedly been found that a 0.87 g daily dose ofa formulation comprising 0.52 mg estrogen according to the inventionthat provides an estimated nominal daily estrogen dose of about 10 toabout 15 micrograms, and a resulting serum level of estradiol of about25 to about 50 pg/ml, is effective at treating hot flashes in subjectsundergoing treatment. In one embodiment, this dose is the lowesteffective dose of estrogen to treat hot flashes.

The formulation of the invention comprises estrogen in an amount fromabout 0.45 mg to about 0.6 mg; and a delivery vehicle, which may, in oneembodiment, comprise a C₂ to C₄ alkanol, a polyalcohol, and a permeationenhancer of monoalkyl ether of diethylene glycol present in an amountsufficient to provide permeation enhancement of the active agent throughmammalian dermal or mucosal surfaces.

In one embodiment, the formulation is administered in an amount of fromabout 0.75 g to about 1 g daily, preferably from about 0.85 g to about0.9 g daily, and more preferably in an amount of about 0.87 g daily. Inanother embodiment, the formulation comprises from about 0.01% to about10% by weight of estrogen. In a more preferred embodiment, theformulation comprises about 0.06% by weight of estrogen, correspondingto about 0.45 mg estrogen in a 0.75 g dose of the formulation, about0.52 mg in a 0.87 g dose of the formulation, and about 0.6 mg estrogenin a 1 g dose of the formulation.

In one embodiment, the formulation provides an estimated nominal dailyestrogen dose of from about 10 to about 15 micrograms, preferably fromabout 11 to about 14 micrograms, more preferably from about 12 to about13 micrograms, and even more preferably an estimated nominal dailyestrogen dose of about 12.5 micrograms.

In another embodiment, the amount of estrogen which is administered iseffective to produce a resulting serum estradiol level of between about25 pg/ml to about 50 pg/ml, preferably an amount of between about 30pg/ml to about 40 pg/ml, and most preferably an amount about 34.4 pg/ml,in subjects receiving the formulation.

In one currently preferred embodiment, the formulation is administeredin an amount of about 0.87 g daily, comprises about 0.06% by weightestrogen (corresponding to about 0.52 mg estrogen), the estimatednominal daily estrogen dose provided by the formulation is about 12.5micrograms, and the resulting serum estradiol level is about 34.3 pg/ml.

Advantageously, the formulations are substantially free of long-chainfatty alcohols, long chain fatty acids and long-chain fatty esters, thusavoiding potential undesirable odor and irritation effects caused bysuch compounds during use of the formulation. Thus, advantageously, theformulations of the present invention do not include theundesirable-odor causing and irritation causing permeation enhancersthat were once thought to be necessary for such transdermal ortransmucosal formulations.

In accordance with the invention, the polyalcohol can be advantageouslypresent in an amount between about 1% and 30% by weight of the vehicle.The monoalkyl ether of diethylene glycol can be present in an amount ofabout 0.2% and 25% by weight of the vehicle and the alkanol can bepresent in an amount between about 5 to 75% by weight of the vehicle.Generally, the alkanol can be present in a hydroalcoholic mixture withwater.

The alkanol can be an ethanol, isopropanol, or n-propanol. Preferably,the alkanol is ethanol. The polyalcohol can be propylene glycol,butylene glycol, hexylene glycol, and ethylene glycol. Preferably, thepolyalcohol is propylene glycol. The permeation enhancer of monoalkylether of diethylene is, for example, diethylene glycol monoethyl etheror diethylene glycol monomethyl ether. Preferably, the permeationenhancer is diethylene glycol monoethyl ether.

The estrogen can be present in any form known in the art, for example,17 beta-estradiol, estradiol, estradiol benzoate, estradiol 17beta-cypionate, estriol, estrone, ethinyl estradiol, mestranol,moxestrol, mytatrienediol, polyestradiol phosphate, quinestradiol, andquinestrol, or any combination thereof. Estradiol is the preferredestrogen.

The formulation can further include at least one of a gelling agent,neutralizing agent; buffering agent, moisturizing agent, humectant,surfactant, antioxidant, emollient, or buffer, and the like. Theformulation can be applied in the form of a gel, lotion, cream, spray,aerosol, ointment, emulsion, suspension, liposomal system, lacquer,patch, bandage, or occlusive dressing and the like.

The formulations can be administered to male and female subjectssuffering from hot flashes. In one embodiment the subject is a female,e.g., a postmenopausal woman. In another embodiment, the subject is amale. In another embodiment, the subject has an estrogen deficiency.

The invention also relates to a method of preparing a topical ortransmucosal formulation for delivering the lowest effective dose ofestrogen for treating hot flashes in a subject, and to the resultantcompositions that are prepared. To prepare the formulation, a deliveryvehicle is formed by mixing together a C₂ to C₄ alkanol, a polyalcohol,and a permeation enhancer of monoalkyl ether of diethylene glycolpresent in an amount sufficient to provide permeation enhancement of theactive agent through dermal or mucosal surfaces; and then estrogen isprovided or included in the delivery vehicle in an amount that providesa daily dosage of from about 0.45 mg to about 0.6 mg.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and benefits of the invention will now become more clearfrom a review of the following detailed description of illustrativeembodiments and the accompanying drawings, wherein:

FIG. 1 is a graph depicting mean change from baseline in dailymoderate-to-severe hot flash rate following administration of Bio-E Gel®0.87 g/day (♦), 1.7 g/day (), 2.6 g/day (▪), and placebo (▴).

FIG. 2 is a graph depicting mean change from baseline in daily hot flashseverity following administration of Bio-E Gel® 0.87 g/day (♦), 1.7g/day (), 2.6 g/day (▪), and placebo (▴).

FIG. 3 is a graph depicting median trough concentrations of Bio-E Gel®over time following repeated administration of Bio-E gel 0.87 g/day (♦),1.7 g/day (▪), 2.6 g/day (▪), and placebo (▴).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides compositions and methods for treating hotflashes, by administering to a subject in need of such treatment atopical transdermal or transmucosal formulation, the formulationcomprising an amount of estrogen which is effective at treating hotflashes, and a transdermally or transmucosally acceptable deliveryvehicle. A preferred delivery vehicle comprises a C₂ to C₄ alkanol, apolyalcohol, and a permeation enhancer of monoalkyl ether of diethyleneglycol present in an amount sufficient to provide permeation enhancementof the active agent through mammalian dermal or mucosal surfaces.

As demonstrated herein, the Applicants have found that the formulationsof the present invention are effective at treating hot flashes atunexpectedly low doses. In accordance with the invention, the amount ofestrogen which is administered is from about 0.45 mg to about 0.6 mgdaily, preferably about 0.52 mg daily. The amount of estrogen is, in oneembodiment, the lowest effective dose which is effective at treating hotflashes in a subject in need thereof.

The formulation can comprise from about 0.01% to about 10% by weight ofestrogen. In one embodiment, the formulation comprises from about 0.01%to about 5% by weight of estrogen. In another embodiment, theformulation comprises from about 0.01% to about 1% by weight ofestrogen. In another embodiment, the formulation comprises from about0.01% to about 0.5% by weight of estrogen. In another embodiment, theformulation comprises from about 0.01% to about 0.1% by weight ofestrogen. In a currently preferred embodiment, the formulation comprisesabout 0.06% by weight of estrogen.

The formulations of the invention can be administered in any amount thatis determined safe and effective at treating hot flashes, and preferablycontain estrogen at the lowest effective dose to treat hot flashes in asubject undergoing treatment. The estrogen dose will, of course, dependon a variety of factors such as the weight, age, sex, body fat and rateof metabolism of the subject being treated, and can be determined by aperson of skill in the art. In one embodiment, the estrogen dose is fromabout 0.45 mg to about 0.6 mg, preferably from about 0.5 mg to about0.55 mg, more preferably about 0.52 mg.

Typical total amount of the formulation (i.e., estrogen and deliveryvehicle) to be administered range from about 0.1 g to about 10 g daily.In one embodiment, the formulation is administered in an amount of fromabout 0.25 g to about 5 g daily. In another embodiment, the formulationis administered in an amount of from about 0.75 g to about 1 g daily. Inyet another embodiment, the formulation is administered in an amount offrom about 0.85 g to about 0.9 g daily. In a currently preferredembodiment, the formulation is administered in an amount of about 0.87 gdaily.

In one embodiment, the amount of estrogen which is administered producesa resulting serum estradiol level of between about 25 pg/ml to about 50pg/ml or less in a subject receiving the formulation. In anotherembodiment, the amount of estrogen which is administered is effective toproduce a resulting serum estradiol level of between about 30 pg/ml toabout 40 pg/ml or less. In yet another embodiment, the amount ofestrogen which is administered is effective to produce a resulting serumestradiol level of about 34.3 pg/ml or less. As demonstrated herein,these low daily dose levels have unexpectedly been found to be effectiveat treating hot flashes.

In one embodiment, the formulation provides an estimated nominal dailyestrogen dose of from about 10 to about 15 micrograms in a subjectreceiving the formulation. In another embodiment, the formulationprovides an estimated nominal daily estrogen dose of from about 11 toabout 14 micrograms. In another embodiment, the formulation provides anestimated nominal daily estrogen dose of from about 12 to about 13micrograms. In a currently preferred embodiment, the formulationprovides an estimated nominal daily estrogen dose of about 12.5micrograms.

In one currently preferred embodiment, the formulation is administeredin an amount of about 0.87 g daily, the estimated nominal daily estrogendose provided by the formulation is about 12.5 micrograms, and theresulting serum estradiol level is about 34.3 pg/ml. The formulation ofthe preferred embodiment comprises about 0.06% by weight estrogen,corresponding to about 0.52 mg estrogen per 0.87 g of the formulation.

As used herein, the term “treating” includes ameliorating, preventing,suppressing, inhibiting or reducing the incidence of, or alleviating thesymptoms or severity of hot flashes.

The formulations of the present invention can be clear, water washable,cool to the touch, quick drying, spreadable and/or a non-greasyformulations, such as a gel. In other aspects of the invention, theformulation can be a spray, ointment, aerosol, patch, buccal andsublingual tablets, suppositories, vaginal dosage form, or other passiveor active transdermal devices for absorption through the skin or mucosalsurface. The formulations of the present invention can be applieddirectly to the skin such as by, for example and not limitation, a gel,ointment, or cream or indirectly though a patch, bandage, or otherocclusive dressing.

Advantageously, the substantial omission of the long chain fattyalcohols, long-chain fatty acids, and long-chain fatty esters provides aformulation that does not have the unpleasant odor, irritation, and/orgreasy texture caused by formulations of the prior art that include oneor more of such compounds. Thus, the formulation in accordance with thepresent invention will result in greater patient compliance. In oneembodiment, the formulations are substantially free of such alcohols,fatty acids, and long-chain fatty esters so that the odors associatedwith those compounds do not emanate from the formulation. In thisregard, “substantially free” means an amount which does not impart aperceptible odor to the formulation at a distance of 1 meter or less,preferably an amount which does not impart a perceptible odor to asubject receiving the formulation. Such formulations are also deemed tobe substantially odor free, except for the odor of ethanol, whichevaporates quickly after application. For the purpose of example andillustration, a formulation comprising fatty alcohols, fatty acidsand/or fatty esters in an amount of less than about 0.04% by weight ofthe formulation is substantially odor free.

The present invention relates generally to formulations for providingactive agent, e.g., estrogen, to subjects. The formulations areeffective at treating hot flashes at surprisingly low doses of estradiolin subjects receiving the formulation. In one preferred embodiment, theinvention further relates to formulations for the transdermal ortransmucosal administration of estrogen, that are substantially free ofmalodorous, and irritation causing long-chain fatty alcohols, long-chainfatty acids, and long-chain fatty esters. Surprisingly, the formulationof the present invention can achieve sufficient absorption to result inan effective dosage of the active agent circulating in serum without theinclusion of the long-chain fatty alcohols, the long-chain fatty acidsand the long-chain fatty esters that have been used to date.

The delivery vehicle of the present invention preferably comprises a C₂to C₄ alkanol, a polyalcohol, and a permeation enhancer of monoalkylether of diethylene glycol in an amount sufficient to provide permeationenhancement of the active agent through mammalian dermal or mucosalsurfaces.

In accordance with the invention, the polyalcohol is advantageouslypresent in an amount between about 1% and 30% by weight of the vehicle,preferably from 3% to 20% by weight and more preferably from about 4% to10% by weight. The monoalkyl ether of diethylene glycol is present in anamount of about 0.2% and 25% by weight, preferably between about 1% to15% by weight and more preferably between about 2% to 8% by weight. Thealkanol is present in an amount between about 5 to 75% by weight,preferably between about 15% to 65% by weight, and more preferablybetween about 20% and 55% by weight. The alkanol can be present in ahydroalcoholic mixture with water. The mixture is present in an amountbetween about 40% and 98% by weight of the delivery vehicle, with thealcohol being present in an amount between about 5% to 80% by weight ofthe hydroalcoholic mixture, and the water present in an amount betweenabout 20% to 95% by weight of the hydroalcoholic mixture. Preferably,the alcohol is present in an amount of about 40 to 60% by weight,preferably about 46% by weight and the water in an amount of 40 to 50%by weight, preferably about 41% by weight of the hydroalcoholic mixture.

For example, the monoalkyl ether of diethylene glycol is diethyleneglycol monomethyl ether or diethylene glycol monoethyl ether or mixturesthereof. Also for example, the polyalcohol is propylene glycol,dipropylene glycol or mixtures thereof. The polyalcohol and thepermeation enhancer can be in present in a weight ratio of about 2:1 to1:1. Alternatively, the polyalcohol and permeation enhancer can bepresent in a weight ratio of about 1.25:1 to 1.2 to 1.

For the purpose of illustration and not limitation, the alkanol can be aC₂ to C₄ alcohol such as ethanol, isopropanol, or n-propanol. Thealkanol is preferably ethanol. As known in the art, the amount of thealcoholic component of the formulation can be selected to maximize thediffusion of the active agent through the skin while minimizing anynegative impact on the active agent itself or desirable properties ofthe formulation.

Examples of estrogens which can be useful in this invention includeestrogens such as 17 beta-estradiol, estradiol, estradiol benzoate,estradiol 17 beta-cypionate, estriol, estrone, ethinyl estradiol,mestranol, moxestrol, mytatrienediol, polyestradiol phosphate,quinestradiol, and quinestrol, or any combination thereof.

The formulation may further include a thickening agent or gelling agentpresent in an amount sufficient to alter the viscosity of theformulation. A gelling agent can be selected from the group including:carbomer, carboxyethylene or polyacrylic acid such as Carbopol 980 or940 NF, 981 or 941 NF, 1382 or 1342 NF, 5984 or 934 NF, ETD 2020, 2050,934P NF, 971P NF, 974P NF, Noveon AA-1 USP; cellulose derivatives suchas ethylcellulose, hydroxypropylmethylcellulose (HPMC),ethylhydroxyethylcellulose (EHEC), carboxymethylcellulose (CMC),hydroxypropylcellulose (HPC) (Klucel different grades),hydroxyethylcellulose (HEC) (Natrosol grades), HPMCP 55, Methocelgrades; natural gums such as arabic, xanthan, guar gums, alginates;polyvinylpyrrolidone derivatives such as Kollidon grades;polyoxyethylene polyoxypropylene copolymers such as Lutrol F grades 68,127. Other gelling agents include chitosan, polyvinyl alcohols, pectins,veegum grades. A tertiary amine, such as triethanolamine or trolamine,can be included to thicken and neutralize the system.

A polymer or copolymer of acrylic acid, such as a carbomer acts as agelling forming and facilitates the release of lipophilic active agentand penetration enhancer. Preferably, the gelling agent is Lutrol Fgrades and Carbopol grades. The gelling agent is present from about 0.2to about 30.0% by weight of the formulation depending on the type ofpolymer. For example, the gelling agent is preferably present in anamount between about 0.5% to 2% by weight for polyacrylic acids, andbetween about 1 to 5% by weight for celluloses.

The amount and the type of the gelling agent in the formulation can beselected to provide the desired product consistency and/or viscosity tofacilitate application to the skin.

Preservatives.

The formulation may further include preservatives such as, but notlimited to, benzalkonium chloride and derivatives, benzoic acid, benzylalcohol and derivatives, bronopol, parabens, centrimide, chlorhexidine,cresol and derivatives, imidurea, phenol, phenoxyethanol, phenylethylalcohol, phenylmercuric salts, thimerosal, sorbic acid and derivatives.The preservative is present from about 0.01 to about 10.0% by weightdepending on the type of compound.

Antioxidant.

The formulation may optionally include antioxidants such as but notlimited to tocopherol and derivatives, ascorbic acid and derivatives,butylated hydroxyanisole, butylated hydroxytoluene, fumaric acid, malicacid, propyl gallate, metabisulfates and derivatives. The antioxidant ispresent from about 0.001 to about 5.0% by weight of the formulationdepending on the type of compound.

Buffers.

The formulation may further include buffers such as carbonate buffers,citrate buffers, phosphate buffers, acetate buffers, hydrochloric acid,lactic acid, tartric acid, diethylamine, triethylamine,diisopropylamine, aminomethylamine. Although other buffers as known inthe art can be included. The buffer may replace up to 100% of the wateramount within the formulation.

Humectant.

The formulation may further include humectant, such as but not limitedto glycerin, propylene, glycol, sorbitol, triacetin. The humectant ispresent from about 1 to 10.0% by weight of the formulation depending onthe type of compound.

Sequestering Agent.

The formulation may further include a sequestering agent such as edeticacid. The sequestering agent is present from about 0.001 to about 5.0%by weight of the formulation depending on the type of compound.

Surfactant.

The formulation may further include anionic, non-ionic or cationicsurfactants. The surfactant is present from about 0.1% to about 30.0% byweight of the formulation depending on the type of compound.

pH Regulator.

Optionally, the formulation may include a pH regulator, generally, aneutralizing agent, which can optionally have crosslinking function. Byway of example and not limitation, the pH regulator may include aternary amine such as triethanolamine, tromethamine,tetrahydroxypropylethylendiamine, NaOH solution. The pH regulator ispresent in the formulations in about 0.05 to about 2.0% by weight.

Moisturizers and Emollients.

Optionally, the formulation may include moisturizers and/or emollientsto soften and smooth the skin or to hold and retain moisture. By way ofexample and not limitation, moisturizers and emollients may includecholesterol, lecithin, light mineral oil, petrolatum, and urea.

For any particular formulation, the active agent and other ingredientscan be selected to achieve the desired drug delivery profile and theamount of penetration desired. The optimum pH may also be determined andmay depend on, for example, the nature of the hormone, the base, anddegree of flux required.

In certain preferred embodiments of the present invention, theformulation may have the following formula.

TABLE 1 Estradiol 0.01%-2%   Carbomer 0.05%-4%   Triethanolamine (adjustto pH 5.9) 0.05%-1%   Alcohol 20%-65% Propylene glycol  1%-15%Diethylene glycol monoethyl ether  1%-15% Ion Exchange Purified Water q.ad. 20%-65%

TABLE 2 Estradiol 0.01%-1% Carbomer 940 1.2% Triethanolamine (adjust topH 5.9) 0.4% Alcohol 46.28%  Propylene glycol   6% Diethylene glycolmonoethyl ether   5% Disodium EDTA 0.06%  Ion Exchange Purified Water q.ad. 100% 

TABLE 3 Estradiol 0.06% Ethanol, Dehydrated 46.28%  Propylene Glycol  6% Diethylene glycol monoethyl ether (Transcutol ® P)   5% Carbopol ®980 (Carbomer 940) 1.20% Triethanolamine (Trolamine 99) 0.35%

The formulations of the present invention are advantageous at least forthe following reasons. First, the surprisingly low doses of theformulations give rise to serum levels of estradiol that are effectiveat treating hot flashes. For example, it has unexpectedly been foundthat about 0.87 g of the formulation comprising about 0.52 mg estrogenprovides an estimated nominal daily estrogen dose of about 12.5micrograms, and a resulting serum estradiol level of about 34.3 pg/ml.Surprisingly, this dose has been determined as the lowest effective doseto treat hot flashes. Advantageously, the formulation is safe and isassociated with reduced side effects and risks compared to higher dosespreviously used.

Second, the formulations of the present invention are, in oneembodiment, substantially free of long-chain fatty alcohols, long-chainfatty acids, and long-chain fatty esters. Surprisingly, the formulationsexhibit skin penetration sufficient to deliver an effective dosage ofthe desired active agent(s) to the user. This is an unexpected advantagethat those of ordinary skill in the art would not have readilydiscovered since it had been generally understood that long-chain fattyalcohols, long-chain fatty acids, and long chain fatty esters would berequired to enhance skin penetration to permit an effective dose of anactive agent to penetrate the skin.

Third, because the formulations preferably do not include aliphatic acidgroups, such as fatty acids, that are commonly included in topical gelsor lotions, they do not have the odor or oily texture which isassociated with that ingredient as in presently-available gels orlotions.

Fourth, the absence of long-chain fatty alcohols, long-chain fattyacids, and long-chain fatty esters means that the irritation potentialis lower and that there is less chance for the components to interact,reducing the need for antioxidants or preservatives in the formulations.Numerous studies acknowledge the irritation causing potential ofunsaturated fatty acids such as oleic acid. See, Tanojo H. Boelsma E,Junginger H E, Ponec M, Bodde H E, “In vivo human skin barriermodulation by topical application of fatty acids,” Skin Pharmacol Appl.Skin Physiol. 1998 March-April; 11 (2) 87-97. It is to be understood,however, that if such preservatives are desired, the inventionencompasses formulations which include antioxidants or preservatives.The reduction in the number of ingredients is advantageous at least inreducing manufacturing costs, possible skin irritation and transfer toothers. Additionally, the reduced number of ingredients increases thestorage stability of the formulation by decreasing the chance that theingredients will interact prior to being delivered. This does not,however, imply that additional ingredients cannot be included in theformulation for particular aesthetic and/or functional effects. Forexample, the formulations may optionally include one or moremoisturizers for hydrating the skin or emollients for softening andsmoothing the skin. Glycerin is an example of such a suitablemoisturizing additive.

The formulations of the invention can be applied once daily, or multipletimes per day depending upon the condition of the patient. Theformulation of the invention can be applied topically to any body part,such as the thigh, abdomen, shoulder, and upper arm.

The invention includes the use of the formulations described above totreat subjects to increase circulating levels of active agents withinthe patient.

Preferred dosage units are capable of delivering an effective amount ofthe active agent over a period of about 24 hours. By an “effective” or“therapeutically effective” amount of an active agent is meant anontoxic, but sufficient amount of the agent to provide the desiredeffect. The minimum or lowest effective dose of each active agent is ofcourse preferred to minimize the side effects associated treatment withthe selected active agent(s). The formulation is preferably applied on aregularly timed basis so that administration of the active agents issubstantially continuous.

EXAMPLES

The following examples are illustrative and should not be interpreted aslimiting.

Example 1 Study of the Safety and Efficacy of Topical Bio-E Gel® forTreatment of Vasomotor Symptoms and Vulvovaginal Atrophy Symptoms inPostmenopausal Females

The objectives of this study were to evaluate the safety and efficacy ofBio-E Gel® 0.87 g, 1.7 g and 2.6 g (containing, respectively, 0.52 mg,1.02 mg, and 1.56 mg estradiol), administered as a daily regimen,compared to that of placebo gel in the treatment of vasomotor symptomsand vulvovaginal atrophy symptoms in postmenopausal women. Eligiblesubjects were health post-menopausal women, with an estradiol serumconcentration of ≦2.0 ng/dL, a follicle stimulating hormone (FSH) serumconcentration of >40 mIU/mL, who exhibited ≧60 moderate-to-severe hotflashes each week during the first 2 weeks of screening.

Bio-E Gel® consisted of 0.06% estradiol in a hydroalcoholic gelformulation supplied in a metered-dose bottle that delivered 0.87 g(0.52 mg estrogen) Bio-E Gel®, 1.7 g (1.02 mg estrogen) Bio-E Gel®, or2.6 g (1.56 mg estrogen) Bio-E Gel® per application. Daily topicalapplication of Bio-E Gel® was administered by the subject on the upperarm/shoulder areas.

The parameters evaluated included hot flash rate and severity, vaginalatrophy assessments, adverse effects, safety laboratory tests, vitals,signs, weight, physical and gynecological examinations includingendometrial biopsies and breast examinations, and skin irritation.

Results Vasomotor Symptoms (Primary)

1) Mean Change from Baseline in Daily Moderate-to-Severe Hot Flash RatesOver Time

As demonstrated in FIG. 1 and Table 4, at the Week 4 primary endpoint,each treatment group showed a reduction from baseline in dailymoderate-to-severe hot flash rate, and the change was statisticallysignificantly greater for subjects receiving 1.7 g/day Bio-E Gel® and2.6 g/day Bio-E Gel® than for placebo (−8.2 and −9.5, respectively, vs.−5.4; p<0.0001 for both comparisons). In addition, the differencebetween these Bio-E Gel® groups and the placebo group in their number ofhot flashes per day was >2.0, demonstrating that the reduction was alsoclinically meaningful. For subjects receiving 0.87 g/day Bio-E-Gel® thechange from baseline in daily moderate-to-severe hot flash rateapproached statistical significance difference at Week 4 (−6.6 vs. −5.4;p=0.0965). However, both a clinically and statistically significantdifference from placebo was observed beginning at Week 5, indicatingthat 0.87 g/day is the lowest effective dose of Bio-E Gel® for thereduction of moderate-to-severe hot flashes.

At the Week 12 primary endpoint, the change from baseline in dailymoderate-to-severe in hot flash rate was statistically and clinicallysignificant for subjects receiving 0.87 g/day Bio-E gel, 1.7 g/day Bio-EGel® and 2.6 g/day Bio-E Gel® compared to placebo (−9.1, −10.7, and−11.3, respectively, vs. −6.1; p<0.0001 for both comparisons) (Table 4and FIG. 1).

TABLE 4 Mean Change From Baseline in Daily Moderate-to-Severe Hot flashRate (ITT-LOCF) Mean Change From Baseline^(a) Bio-E gel Bio-E gel Bio-Egel Placebo 0.87 g/day 1.7 g/day 2.6 g/day Evaluation (N = 137) (N =136) (N = 142) (N = 69) Baseline (Mean ± SD)^(b) 13.5 ± 4.5 13.3 ± 4.613.1 ± 6.5 12.9 ± 4.5 Placebo Lead-In −3.0 −2.6 −2.7 −2.6 Week 1 −4.0−3.4 −2.3* −3.0 Week 2 −4.7 −4.6 −4.7 −5.8 Week 3 −5.2 −5.7 −6.9*−8.4*** Week 4 −5.4 −6.6 −8.2*** −9.5*** Week 5 −5.5 −7.7** −9.0***−10.0*** Week 6 −5.7 −7.9** −9.5*** −10.4*** Week 7 −6.0 −8.5*** −9.9***−10.9*** Week 8 −6.0 −8.6*** −10.1*** −11.0*** Week 9 −6.0 −8.7***−10.3*** −11.4*** Week 10 −6.0 −9.0*** −10.5*** −11.3*** Week 11 −6.1−9.0*** −10.5*** −11.3*** Week 12 −6.1 −9.1*** −10.7*** −11.3***^(a)Differences from baseline to each week based on LS means derivedfrom the ANCOVA model with factors for baseline, treatment, site, andtreatment-by-baseline interaction. ^(b)Unadjusted means and standarddeviations. Baseline based on the first 14 days of the Screening Period.*P < 0.01, **P < 0.001, ***P < 0.0001 for treatment comparison withplacebo (Dunnett's test).

2) Mean Change from Baseline in Daily Hot Flash Severity Over Time

As demonstrated in Table 5, at the Week 4 primary endpoint, thereduction from baseline in daily hot flash severity was statisticallysignificantly greater for subjects receiving 1.7 g/day Bio-E Gel® and2.6 g/day Bio-E Gel® than for placebo (−0.7 and −1.0, respectively, vs.−0.3; p<0.0001 for both comparisons). On average, these reductionsplaced subjects in the Bio-E Gel® groups in the category of havingmild-to-moderate hot flash severity, while those in the placebo groupwere still in the moderate-to-severe category. The change for subjectsreceiving 0.87 g/day Bio-E Gel® approached statistical significance fromplacebo (−0.5 vs. −0.3; p=0.0714) at week 4. However, both a clinically(mild-to-moderate vs. moderate-to-severe) and a statisticallysignificant (−0.6 vs. −0.3; p=0.0083) difference from placebo wasobserved for this dose group beginning at Week 5.

At the Week 12 primary endpoint, the change from baseline in daily hotflash severity was statistically significantly greater for subjectsreceiving 0.87 g/day Bio-E gel, 1.7 g/day Bio-E Gel® and 2.6 g/day Bio-EGel® than for placebo (−0.9, −1.4 and −1.6, respectively, vs. −0.4;p<0.001 for all comparisons) (Table 5).

As illustrated in FIG. 2, the reduction from baseline in daily hot flashseverity among subjects receiving Bio-E Gel® was dose-dependent, withprogressively greater effects shown with increasing doses of Bio-E Gel®at each time point studied. In addition, the magnitude of reduction inhot flash severity was dose- and time-dependent. Similarly, the onset ofseverity reduction was dose-dependent, occurring somewhat later forsubjects receiving 0.87 g/day Bio-E Gel® than for those receiving 2.6g/day or 1.7 g/day. Significant differences from placebo in mean changefrom baseline in hot flash severity were noted at Week 5 for subjectsreceiving 0.87 g/day Bio-E Gel® (−0.6 vs. −0.3; p=0.0083), at Week 3 forsubjects receiving 1.7 g/day (−0.5 vs. −0.3; p=0.0031), and at Week 2for subjects receiving 2.6 g/day (−0.4 vs. −0.2; p=0.0210) (Table 5).

TABLE 5 Mean Change From Baseline in Daily Hot flash Severity (ITT-LOCF)Mean Change From Baseline^(a,b) Bio-E gel Bio-E gel Bio-E gel Placebo0.87 g/day 1.7 g/day 2.6 g/day Evaluation (N = 137) (N = 136) (N = 142)(N = 69) Baseline (Mean ± SD)^(c) 2.4 ± 0.3 2.4 ± 0.3 2.4 ± 0.3 2.4 ±0.3 Placebo Lead-In −0.1 −0.1 −0.1 −0.1 Week 1 −0.2 −0.2 −0.1 −0.1 Week2 −0.2 −0.2 −0.3 −0.4^(†) Week 3 −0.3 −0.3 −0.5* −0.7*** Week 4 −0.3−0.5 −0.7*** −1.0*** Week 5 −0.3 −0.6* −0.8*** −1.1*** Week 6 −0.3 −0.6*−0.9*** −1.2*** Week 7 −0.3 −0.7* −1.0*** −1.3*** Week 8 −0.3 −0.7**−1.1*** −1.4*** Week 9 −0.3 −0.8** −1.1*** −1.5*** Week 10 −0.3 −0.8***−1.2*** −1.6*** Week 11 −0.3 −0.9*** −1.2*** −1.5*** Week 12 −0.4−0.9*** −1.3*** −1.6*** ^(a)Differences from baseline to each week basedon LS means derived from the ANCOVA model with factors for baseline,treatment, and site. ^(b)Severity score: 0 = none, 1 = mild, 2 =moderate, 3 = severe. ^(c)Unadjusted means and standard deviations.Baseline based on the first 14 days of the Screening Period. ^(†)P <0.05, *P < 0.01, **P < 0.001, ***P < 0.0001 for treatment comparisonwith placebo (Dunnett's test).

Vulvovaginal Atrophy Symptoms (Primary)

1. Mean Change from Baseline in Most Bothersome Moderate-to-SevereSymptom (Week 12/Last Visit)

The mean change from baseline to Week 12 (or last visit for subjects whodiscontinued prematurely) in subjects' most bothersomemoderate-to-severe vulvovaginal atrophy symptom is presented in Table 6.Approximately half of the subjects in each treatment group identified amost bothersome symptom at baseline that was moderate or severe forinclusion in this analysis. The mean baseline severity of the mostbothersome moderate-to-severe vulvovaginal atrophy symptom ranged from2.23 to 2.48 across treatment groups. At the Week 12 primary endpoint, aclinically meaningful reduction from baseline in severity of mostbothersome vaginal atrophy symptom was observed among subjects receivingactive treatment with Bio-E Gel®. Specifically, the average reductionfrom baseline among subjects receiving 0.87 g/day, 1.7 g/day, and 2.6g/day Bio-E Gel® (−1.74, −1.53, and −1.75, respectively) placed theaverage severity in the range of none to mild, while among thosereceiving placebo, the reduction (−1.31) placed the average severity inthe range of mild to moderate. A statistically significant differencefrom placebo was observed only in the 0.87 g/day Bio-E Gel® group (−1.74vs. −1.31; p=0.0183), which had the largest sample size (N=67) for Week12 data (Table 6). The smaller sample sizes in the higher dose Bio-EGel® treatment groups may explain the lack of significance in thesegroups in comparison to placebo treatment, although the 2.6 g/day groupapproached statistical significance (p=0.0518).

2. Mean Change from Baseline in Vaginal pH (Week 12/Last Visit)

The mean change from baseline to Week 12 (or last visit for subjects whodiscontinued prematurely) in vaginal pH among subjects who had a vaginalpH>5.0 at baseline is presented in Table 6). The mean vaginal pH atbaseline ranged from 6.07 to 6.31 across treatment groups. Relative toplacebo, all Bio-E Gel® treatment groups showed a more acidic vaginal pHat Week 12, with the mean change from baseline in vaginal pH being−1.21, −1.20, and −1.31 in the 0.87 g/day, 1.7 g/day, and 2.6 g/dayBio-E Gel® groups. All reductions were statistically significantly(p<0.0001) greater relative to placebo (−0.17).

3. Mean Change from Baseline in Vaginal Maturation Index (VMI) (Week12/Last Visit)

The VMI among subjects who had ≦5% superficial cells in the vaginal wallspecimen at baseline is presented in Table 6. The mean VMI at baselinewas similar across treatment groups, ranging from 40.6 to 42.3, andincreased (i.e., decreased parabasal cells and increased superficialcells) substantially at Week 12 in all subjects receiving Bio-E gel.While the change in VMI was a score of 1.2 at Week 12 for placebo, themean increase in VMI was approximately 18 in subjects receiving 0.87g/day Bio-E gel, 26 in subjects receiving 1.7 g/day, and 28 in subjectsreceiving 2.6 g/day (p<0.0001 for all Bio-E Gel® groups) (Table 6).

TABLE 6 Mean Change From Baseline^(a) in Most BothersomeModerate-to-Severe Vulvovaginal Atrophy Symptom, Vaginal pH, and VaginalMaturation Index (ITT-Observed Data) Mean Change From Baseline Bio-E gelBio-E gel Bio-E gel Evaluation Placebo 0.87 g/day 1.7 g/day 2.6 g/dayMost bothersome moderate-to- severe vulvovaginal atrophy symptoma^(a,b)N (Baseline/ 64/62 69/67 64/61 35/35 Week 12) Baseline 2.48 ± 0.50 2.36± 0.48 2.23 ± 0.43 2.26 ± 0.44 (Mean ± SD)^(c) Week 12 −1.31 −1.74^(†)−1.53 −1.75 (last visit)^(d) Vaginal pH^(e,f) N (Baseline/ 84/81 68/6680/78 36/34 Week 12) Baseline 6.28 ± 0.71 6.31 ± 0.62 6.18 ± 0.61 6.07 ±0.62 (Mean ± SD)^(c) Week 12 −0.17 −1.21*** −1.20*** −1.31*** (lastvisit)^(d) Vaginal maturation index^(e,g) N (Baseline/ 123/117 119/116117/115 57/56 Week 12) Baseline 40.6 ± 11.9 40.8 ± 12.8 41.5 ± 10.5 42.3± 10.8 (Mean ± SD)^(c) Week 12 1.2 17.9*** 25.9*** 28.3*** (lastvisit)^(d) ^(a)Differences from baseline to Week 12 (last visit) basedon LS means derived from the ANCOVA model with factors for baseline,treatment, and site. ^(b)Based on subject rating of severity (0 = none,1 = mild, 2 = moderate, 3 = severe) of 5 symptoms of vulvovaginalatrophy (dryness, irritation, pain passing urine, pain with sexualactivity, bleeding with sexual activity) on the Vaginal HealthSelf-Assessment Questionnaire. Only those subjects who identified atleast 1 moderate-to-severe symptom that was most bothersome to her areincluded in the analyses. ^(c)Unadjusted means and standard deviations.Baseline based on the Visit 1 (Day −21) assessment. ^(d)Assessments weremade at Week 12 or at last visit for subjects who discontinuedprematurely. ^(e)Differences from baseline to Week 12 (last visit) basedon LS means derived from the ANCOVA model with factors for baseline,treatment, site, and treatment-by-baseline interaction. ^(f)Only thosesubjects who had vaginal pH >5.0 at baseline are included in theanalyses. ^(g)Only those subjects who had ≦5% superficial cells in thevaginal wall specimen at baseline are included in the analyses. ^(†)P <0.05, ***P < 0.0001 for treatment comparison with placebo (Dunnett'stest).

Estradiol Dose, Concentration, and Relationships to Response

Mean, median, and range of trough serum concentrations of estradiol, atentry into the Double-Blind Treatment Period (Day 1) and at Week 4, Week8, and Week 12 of the Double-Blind Treatment Period are presented inTable 7; median trough serum concentrations are presented in FIG. 3.

Mean trough levels of estradiol were very similar across treatmentgroups at Day 1 and increased only in subjects receiving Bio-E Gel® atsubsequent time points. At Week 4 and continuing through Week 12, meantrough levels of estradiol were significantly higher among subjectsreceiving any dose of Bio-E Gel® than among those receiving placebo.Furthermore, the median serum estradiol values increased in adose-dependent fashion as Bio-E Gel® dose increases (FIG. 3). Mean serumlevels of estradiol in the 1.7 g/day and 2.6 g/day groups at Week 4,Week 8, and Week 12 were similar. A recalculation of the 1.7 g/day doseat Day 29 and Day 57 was performed to exclude two extreme outliers. AtDay 29 the median estradiol value for the 1.7 g/day dose did not change(23 pg/mL), but the mean±SD serum estradiol changed from 41.7±73.4 pg/mLto 36.9±48.7 pg/mL while analysis of the serum estradiol at Day 57changed from 42.7±99.0 pg/mL to 34.5±32.4 pg/mL and the median wasunchanged (23.0 pg/mL). With this recalculation there is adose-dependent increase in the median serum estradiol and anapproximately dose-dependent increase in mean serum estradiolconcentrations.

TABLE 7 Trough Serum Concentrations of Estradiol Over Time (ITT-ObservedData) Hormone [Normal Bio-E gel Bio-E gel Bio-E gel Range]^(a)Evaluation Placebo 0.87 g/day 1.7 g/day 2.6 g/day Estradiol Day 1, N 136133 142 68 [30-300] Mean ± SD 12.4 ± 10.6 13.2 ± 14.8  11.2 ± 10.1   9.7± 2.9  (pg/mL) Median 9.0 9.0 9.0 9.0 Range 9-75  9-140 9-95  9-27  Day29 131 130 136 67 (Week 4), N Mean ± SD 13.3 ± 18.1 30.4 ± 35.3^(†) 41.7± 73.4*** 35.8 ± 33.8* Median 9.0 19.0 23.0 27.0 Range 9-130 9-230 9-6809-190 Day 57 123 130 132 64 (Week 8), N Mean ± SD 12.3 ± 15.6 31.0 ±35.5^(†) 42.7 ± 99.0**  41.1 ± 41.9* Median 9.0 19.0 23.0 26.0 Range9-140 9-210  9-1110 9-230 Day 85 128 131 138 67 (Week 12), N Mean ± SD14.3 ± 28.0  34.3 ± 43.8** 38.7 ± 42.3***  40.8 ± 37.1*** Median 9.020.0 23.5 29.0 Range 9-310 9-330 9-230 9-200 ^(a)Normal range is forpremenopausal women (see Section 9.5.4) ^(†)P < 0.05, *P < 0.01, **P <0.001, ***P < 0.0001 for comparison of LS means for each Bio-E Gel ®treatment group with placebo (Dunnett's test).

Conclusions

For the primary efficacy outcomes of hot flash rate and hot flashseverity, statistically significant reductions in dailymoderate-to-severe hot flash rate were observed for all doses of Bio-EGel® compared to the placebo, starting at Week 5 for the 0.87 g/day dose(p=0.0965 at Week 4), and at Week 3 for the 1.7 g/day and 2.6 g/daydoses. A clinically meaningful reduction in hot flash rate compared tothe placebo-treated group was first seen at Week 5, 4, and 3 for studygroups receiving 0.87 g/day Bio-E gel, 1.7 g/day Bio-E Gel® and 2.6g/day Bio-E gel, respectively. Reductions in hot flash severity werestatistically significantly different from placebo treatment by Week 5for the 0.87 g/day dose (p=0.0714 at Week 4), by Week 3 for the 1.7g/day, and by Week 2 for the 2.6 g/day doses of Bio-E gel. Reductions indaily moderate-to-severe hot flash rate that were both clinicallymeaningful and statistically significant and reductions in hot flashseverity that were statistically significant were maintained from timeof onset through Week 12 for all Bio-E Gel® dose groups.

Regarding estradiol concentrations, treatment with increasing doses ofBio-E Gel® showed a dose-dependent increase in median troughconcentrations of estradiol and an approximately dose-dependent increasein mean concentrations of estradiol. The effects of Bio-E Gel® onvasomotor symptoms were dose-related and were consistent with thedose-related increases observed in median serum concentrations ofestradiol.

Efficacy outcomes in this study support 0.87 g/day as the lowesteffective dose of Bio-E Gel® for the treatment of vasomotor symptoms andvulvovaginal atrophy symptoms in postmenopausal women.

Safety:

The general findings of this study with respect to the safety of Bio-EGel® was that it was well-tolerated locally, with few subjectsexperiencing application site reactions. Bio-E Gel® did not produce anyadverse events that were not already well-recognized for estrogen drugproducts used for the treatment of vasomotor and vulvovaginal symptomsassociated with menopause.

The overall incidence of treatment-emergent adverse events increasedwith increasing dose of Bio-E Gel® (59% to 68% across the three doses)and was slightly higher than the incidence in the placebo group (56%).Treatment-emergent adverse events that occurred in >5% of subjectsduring 12-week treatment for all Bio-E Gel® doses were nausea,peripheral edema, breast tenderness, metrorrhagia, vaginal discharge,nipple pain, endometrial hyperplasia, nasopharyngitis, and upperrespiratory tract infection.

Study Conclusions:

The results of this study demonstrate that Bio-E Gel® effectivelyreduces vasomotor and vulvovaginal symptoms associated with menopause.Given the efficacy of the low dose (0.87 g/day) of Bio-E Gel® along withits ability to significantly increase estradiol levels and comparativesafety relative to the higher doses (1.7 g/day and 2.6 g/day), 0.87g/day Bio-E Gel® is considered to be the lowest effective dose for thetreatment of vasomotor symptoms and vulvovaginal symptoms inpostmenopausal women.

While the specification describes particular embodiments of the presentinvention, those of ordinary skill can devise variations of the presentinvention without departing from the inventive concept. Thus, theinvention described and claimed herein is not to be limited in scope bythe specific embodiments disclosed herein, since these embodiments areintended as illustrations of several aspects of the invention. Anyequivalent embodiments are intended to be within the scope of theinvention. Indeed, various modifications of the invention in addition tothose shown and described herein will become apparent to those skilledin the art from the foregoing description. Such modifications are alsointended to fall within the scope of the appended claims.

1. A method for treating hot flashes, which comprises administering to asubject in need of such treatment a daily dosage of from about 0.45 mgto about 0.6 mg per day of estrogen from a topical or transmucosalformulation over a period of at least five weeks, wherein the amount ofestrogen that is administered daily is the lowest effective dose totreat hot flashes in the subject.
 2. The method of claim 1, wherein thedaily dosage is administered by applying an amount of about 0.1 g toabout 10 g of a topical or transmucosal formulation comprising: about0.01% to 10% by weight of estrogen; and a delivery vehicle comprising aC₂ to C₄ alkanol, a polyalcohol, and a permeation enhancer of monoalkylether of diethylene glycol present in an amount sufficient to providepermeation enhancement of the active agent through dermal or mucosalsurfaces.
 3. The method of claim 1, wherein the daily dosage isadministered by applying an amount of about 0.25 g to about 5 g of atopical or transmucosal formulation comprising: about 0.01% to 5% byweight of estrogen, and a delivery vehicle comprising a C₂ to C₄alkanol, a polyalcohol, and a permeation enhancer of monoalkyl ether ofdiethylene glycol, wherein the polyalcohol is present in an amountbetween about 1% and 30% by weight of the vehicle, the alkanol ispresent in an amount of 5 to 75% by weight of the vehicle, and thepermeation enhancer is present in an amount of between about 0.2% and25% by weight of the vehicle.
 4. The method of claim 3, wherein thepolyalcohol and permeation enhancer are present in a weight ratio of1.25:1 to 1.2:1 and the formulation further comprises a gelling agentpresent in an amount of between 0.05% to about 4% by weight of theformulation, a neutralizing agent present in an amount between about0.05% and 1% by weight of the formulation, and water present in anamount between about 20% to 65% by weight of the formulation so that theformulation is provided as a gel.
 5. The method of claim 1, wherein thedaily dosage is administered by applying an amount of about 0.75 g toabout 1 g of a topical or transmucosal formulation comprising: about0.01% to 0.5% by weight of estrogen, and a delivery vehicle comprising aC₂ to C₄ alkanol, a polyalcohol, and a permeation enhancer of monoalkylether of diethylene glycol, wherein the polyalcohol is present in anamount between about 1% to 15% by weight of the formulation, the alkanolis present in an amount between about 20 to 65% by weight of theformulation, and the permeation enhancer is present in an amount betweenabout 1% to 15% by weight of the formulation.
 6. The method of claim 5,wherein the formulation is applied in an amount of from about 0.85 g toabout 0.9 g with the estrogen present in an amount of about 0.06% byweight of the formulation, and wherein the polyalcohol is polypropyleneglycol, the alkanol is selected from the group consisting of ethanol,isopropanol and n-propanol, and the permeation enhancer is diethyleneglycol monoethyl ether.
 7. The method of claim 1, wherein the subject isfemale and the amount of estrogen which is administered daily iseffective to produce a serum estradiol level in the subject of betweenabout 25 pg/ml to about 50 pg/ml, and wherein the estimated nominaldaily estrogen dose provided by the formulation is from about 10 toabout 15 micrograms.
 8. The method of claim 1, wherein the estrogen isestradiol and the formulation is substantially free of long-chain fattyalcohols, long-chain fatty acids, and long-chain fatty esters in orderto avoid undesirable odor and irritation effects caused by suchcompounds during use of the formulation.
 9. The method of claim 1,wherein the estrogen is selected from the group consisting of 17beta-estradiol, estradiol, estradiol benzoate, estradiol 17beta-cypionate, estriol, estrone, ethinyl estradiol, mestranol,moxestrol, mytatrienediol, polyestradiol phosphate, quinestradiol,quinestrol, and any combination thereof.
 10. The method of claim 1,wherein the formulation further comprises at least one of a gellingagent, neutralizing agent, sequestering agent, buffering agent,moisturizing agent, humectant, surfactant, antioxidant, emollient, orbuffer.
 11. The method of claim 10, wherein the gelling agent isselected from the group consisting of carbomer, carboxyethylene,polyacrylic acid, cellulose derivatives, ethylcellulose,hydroxypropylmethylcellulose, ethylhydrooxyethylcellulose,carboxymethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose,natural gums, arabic, xanthan, guar gums, alginates,polyvinylpyrrolidone derivatives, polyoxyethylene polyoxypropylenecopolymers, chitosan, polyvinyl alcohol, pectin, and veegum; thebuffering agent is selected from the group consisting of carbonatebuffers, citrate buffers, phosphate buffers, acetate buffers,hydrochloric acid, lactic acid, tartric acid, diethylamine,triethylamine, diisopropylamine, tetrahydroxypropylethylendiamine, andaminomethylamine; and the sequestering agent is edetic acid.
 12. Themethod of claim 1, wherein the formulation is in the form of a gel,lotion, cream, spray, aerosol, ointment, emulsion, suspension, liposomalsystem, lacquer, or non-occlusive dressing.
 13. The method of claim 1,wherein the formulation has the following composition: Estradiol0.01%-2%   Carbomer 0.05%-4%   Triethanolamine (adjust to pH 5.9)0.05%-1%   Alcohol 20%-65% Propylene glycol  1%-15% Diethylene glycolmonoethyl ether  1%-15% Ion Exchange Purified Water q. ad. 20%-65%


14. The method of claim 1, wherein the formulation has the followingcomposition: Estradiol 0.01%-1% Carbomer 940 1.2% Triethanolamine(adjust to pH 5.9) 0.4% Alcohol 46.28%  Propylene glycol   6% Diethyleneglycol monoethyl ether   5% Disodium EDTA 0.06%  Ion Exchange PurifiedWater q. ad. 100% 


15. The method of claim 1, wherein the formulation has the followingcomposition: Estradiol 0.06% Ethanol, Dehydrated 46.28%  PropyleneGlycol   6% Diethylene glycol monoethyl ether   5% Carbomer 940 1.20%Triethanolamine 0.35% Ion Exchange Purified Water q. ad.  100%